1. Field of the Invention
The present invention relates to a semiconductor device and a method of fabricating the same, and, more particularly, to a semiconductor device which can be miniaturized and has a wiring layer made of an aluminum alloy having high electro-migration resistance, and to a method of fabricating the same.
2. Description of Related Art
In semiconductor devices such as LSIs, recent advances in miniaturization, integration, and multi-layering of electronic elements have required through-holes with a large aspect ratio. It is difficult to embed wiring materials into such through-holes, and this has become an important technical problem in recent years. Therefore, attempts have been made to embed aluminum or an aluminum alloy which is useful as a wiring material into the through-holes.
Customary methods, however, require high temperature in sputtering to bury aluminum or an aluminum alloy in a through-hole. As the temperature increases, whiskers are easily produced, causing short circuits between wires, and aluminum of a wiring layer in the through-hole reacts with silicon in a substrate giving easy rise to electrical characteristic problems such as leaks. Recent advances in miniaturization and integration of electronic elements have required further flatness of deposited layers and also formation of a thinner film of wiring layers. However, if the wiring layer is thin, the electro-migration resistance is reduced and hence conventionally used aluminum alloy materials cannot adequately cope with this phenomenon.